// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package discover
import (
"crypto/ecdsa"
"encoding/hex"
"fmt"
"math/rand"
"net"
"sync"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
)
var nullNode *enode.Node
func init() {
var r enr.Record
r.Set(enr.IP{0, 0, 0, 0})
nullNode = enode.SignNull(&r, enode.ID{})
}
func newTestTable(t transport) (*Table, *enode.DB) {
db, _ := enode.OpenDB("")
tab, _ := newTable(t, db, nil)
return tab, db
}
// nodeAtDistance creates a node for which enode.LogDist(base, n.id) == ld.
func nodeAtDistance(base enode.ID, ld int, ip net.IP) *node {
var r enr.Record
r.Set(enr.IP(ip))
return wrapNode(enode.SignNull(&r, idAtDistance(base, ld)))
}
// idAtDistance returns a random hash such that enode.LogDist(a, b) == n
func idAtDistance(a enode.ID, n int) (b enode.ID) {
if n == 0 {
return a
}
// flip bit at position n, fill the rest with random bits
b = a
pos := len(a) - n/8 - 1
bit := byte(0x01) << (byte(n%8) - 1)
if bit == 0 {
pos++
bit = 0x80
}
b[pos] = a[pos]&^bit | ^a[pos]&bit // TODO: randomize end bits
for i := pos + 1; i < len(a); i++ {
b[i] = byte(rand.Intn(255))
}
return b
}
func intIP(i int) net.IP {
return net.IP{byte(i), 0, 2, byte(i)}
}
// fillBucket inserts nodes into the given bucket until it is full.
func fillBucket(tab *Table, n *node) (last *node) {
ld := enode.LogDist(tab.self().ID(), n.ID())
b := tab.bucket(n.ID())
for len(b.entries) < bucketSize {
b.entries = append(b.entries, nodeAtDistance(tab.self().ID(), ld, intIP(ld)))
}
return b.entries[bucketSize-1]
}
type pingRecorder struct {
mu sync.Mutex
dead, pinged map[enode.ID]bool
n *enode.Node
}
func newPingRecorder() *pingRecorder {
var r enr.Record
r.Set(enr.IP{0, 0, 0, 0})
n := enode.SignNull(&r, enode.ID{})
return &pingRecorder{
dead: make(map[enode.ID]bool),
pinged: make(map[enode.ID]bool),
n: n,
}
}
func (t *pingRecorder) self() *enode.Node {
return nullNode
}
func (t *pingRecorder) findnode(toid enode.ID, toaddr *net.UDPAddr, target encPubkey) ([]*node, error) {
return nil, nil
}
func (t *pingRecorder) waitping(from enode.ID) error {
return nil // remote always pings
}
func (t *pingRecorder) ping(toid enode.ID, toaddr *net.UDPAddr) error {
t.mu.Lock()
defer t.mu.Unlock()
t.pinged[toid] = true
if t.dead[toid] {
return errTimeout
} else {
return nil
}
}
func (t *pingRecorder) close() {}
func hasDuplicates(slice []*node) bool {
seen := make(map[enode.ID]bool)
for i, e := range slice {
if e == nil {
panic(fmt.Sprintf("nil *Node at %d", i))
}
if seen[e.ID()] {
return true
}
seen[e.ID()] = true
}
return false
}
func contains(ns []*node, id enode.ID) bool {
for _, n := range ns {
if n.ID() == id {
return true
}
}
return false
}
func sortedByDistanceTo(distbase enode.ID, slice []*node) bool {
var last enode.ID
for i, e := range slice {
if i > 0 && enode.DistCmp(distbase, e.ID(), last) < 0 {
return false
}
last = e.ID()
}
return true
}
func hexEncPubkey(h string) (ret encPubkey) {
b, err := hex.DecodeString(h)
if err != nil {
panic(err)
}
if len(b) != len(ret) {
panic("invalid length")
}
copy(ret[:], b)
return ret
}
func hexPubkey(h string) *ecdsa.PublicKey {
k, err := decodePubkey(hexEncPubkey(h))
if err != nil {
panic(err)
}
return k
}
